ML18030A252

Draft Emergency Procedure E0-00-014, Anticipated Transient W/Failure to Scram.

ML18030A252
Person / Time
Site:	Susquehanna
Issue date:	04/15/1981
From:	PENNSYLVANIA POWER & LIGHT CO.
To:
Shared Package
ML18030A253	List: ML18030A252 ML18030A532
References
E--14-DRFT, E0-00-014-DRFT, NUDOCS 8104170311
Download: ML18030A252 (5)

Text

PENi LVANIA POWER 6 LIGHT COiPA.'7Y SUSQUEHANNA SES UNXTS 1 & 2 PROCEDURE APPROVAL FORMAL E fective Date TITLE: EO-00.-014 REVISION C ANTICIPATED TRANSIENT MITE FAXLURE TO SCRA.I (ATt'OS) " E 4 PORC R VI-Ã REQUIRED: YES ( ) NO ( )

Meeting Numoer ORIGINATOR: Dave Smith.

APPROVALS:

SECTION HEAD DATE SUPERINTEND NT OF PLANT DATE 1.0 SlwimTOxfS A.tD OBSERVATIONS A. A valid scram signal is present and all control rods do not insert as indicated on the full core display, RSCS rods "full-in indication", the print/out display of OD-7(NSS-3) "Present Control Rod Positions" and tne Four Rod display.

Neutron flux does not decrease rapidly as in a nor,.al scram.

C. Reactor pressure vessel pressure may 'ncrease causing safety relief valves to operate.

2.0 AUTCiUTIC ACTIONS A. Recirculation pumps trip on ATWOS signals of:

1. -38" RPV level

2. 1135 psig RPV pressure

$ '$0/3.'P 6%1 FORS AD-00-001-1, Rev. 1 Page 1 of 1

EO-00-014 Revision C Page 2 of 4 B. Safety Relief valves may operate.

C. Scram Condition Alarms

1) RX AUTO SCRA"1 CHAiVNEL Al/A2

2) RX AUTO SCAN CHANNEL Bl/B2

3) Valid channel A and channel B scram alarm 3.0 IiQKDIATE OPERATOR ACTIONS A. ifanually trip recirculation pumps A and B.

B. ilanually scram the Reactor as follows:

1) ARi'1 and depress the manual scram pushbuttons.

2) Place the mode switch in SHUTDOWN.

NOTE: If the reactor scrams, perform EO-00-001 and do not continue this procedure.

C. If'he above actions do not scram the reactor, perform any or all of the following to place the reactor in a subcritical condition.

1. Start the 2nd CRD pump a) Place the CRD flow controller in manual and fully open the flow control valve (1(2)-46-FV-1F002A(B))

b) Fully open the CRD drive water pressure control valve (1(2)-

46-PV-1F003).'pen REACTOR PROT SYS TRIP SYS A supply breaker (BKRg ) on panel Y201A and open REACTOR PROT SYS TRIP SYS B supply breaker (BEVY

) on panel Y201B.

3. Isolate and bleed air from the scram air header by closing valve l(2)-47-1F095 and opening valve 1(2)-47-007.

4. Individually scram the control rods at the HCU by placing the test switches (2 at each HCU) in test.

EO"00-014 Revision C Page 3 of 4

5. Inject SBLC per ON-53-001 if either of the following conditions exist:

a) >5 adjacent control rods and/or > 30 control rods total are

>notch 06 following a reactor scram and one or both of the following exist:

1) reactor water level cannot be maintained OR

2) suppression pool water temperature reaches llO~F b) The Control Rod Drive system is incapable of shutting down the Reactor and one or more of the following exist:

1) Reactor power starts to increase as indicated by both nuclear instrumentation and steam flow OR

2) Calculations indicate that criticality will be reached in the next hour OR

3) In the judgement of shift supervision, a hazard exists to the environs, personnel or the plant.

4.0 SUBSEQUENT OPERATOR ACTlON A. If the reactor was scramed by the immediate actions, refer to EO-00-001 (REACTOR SCRAM) and discontinue this procedure.

B. If reactor pressure is causingSRV'sthe safety relief valves (SRV's) to pressure to cycle, manually open enough to reduce Reactor < 920 psig. If subsequent SRV operation is required, the va1ves should be cycled in alphabetical order, if possible, to minimize local heat full loading of the suppression pool. The HPIC system may be placed in flow test to minimize SRV sycling (if not already in service).

C. The RHR system must be placed in the suppression pool cooling mode as soon as practical. (Refer to EO-00-023 CONTAIRfENT CONTROL and OP 001 RHR SYSTEM).

EO-00-014 Revision C Page 4 of 4 5.0 DISCUSSION An "anticipated transient without SCK4'1" (ATMOS) is a SCKQJ condition existing with either no control rods being inserted or not enough control rods being inserted to prevent a restart. Mhile an ATMOS is extremely unlikely, if it did occur, prompt operator action would be required to mitigate the consequences. Haj or operator concerns are as follows:

1. Verify the recirculation pumps trip

2. Shutdown of the reactor

3. Limit RPV peak pressure ifaintain the core cover

5. Limit the temperature of the suppression pool/chamber

6. Long term cooldown The operator must insert enough negative reactivity into the core so that an uncontrolled restart will not occur, this by the most readily available means. The consequences of this accident to the containment and environment must be evaluated, and if it is deemed necessary, the Susquehanna SES Emergency Plan should be initiated.